Power-transmitting mechanism for drills and the like



, f F. H. MILLS, POWER TRANSMITTING MECHANISM FOR DRQLLS AND THE LIKE.

AEPLICATION FILED JAN- IB. 19H. 1,303,356. Patented May 13,1919.

5 SNEEIS-SHEET 1.

F. H. MILLS. POWER TRANSMITTING MECHANISM FOR DRILLSIAND THE LIKE.

APPLICATION FILED TAN. IN, 1911.

Patented May 13, 1919.

s SHEETS-SHEET 2.

INVENTOR M ATTORNEY I I A 77/69. In \H. \I I.

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POWER TRANSMITTING MEGHANTSM FOR DRILLS AND THE LIKE.

' APPLICATION FILEDJAN. 18. an.

I 1,303,356. Patented MaylS, 1919.

5 SHEETS-SHEET a.

Ill

ATTORNEY F. H. MILLS.

.POWER TRANSMITTING MECHANISM FOR DRILLS AND THE LIKE.

APPLICATION r1120 JAN. 18, 1911. v

1,303,356. I Patented May 13, 1919.

5 SHEETS-SHEET 4.

VII

I I INVENTOR WITNESSES ATTORNEY F. H. MILLS.

' POWER TRANSMITTING MECHANISM FOR DRILLS AND THE LIKE.

APPLICATION FILED JAN. 19. um.

Patented May 13, 1919.

5 SHEETS-SHEET 5- ATTORNEY WITNESSES FRANK n. Mints, or CAMDEN, new JERSEY.

POWER-TRANSMITTING MECHANISM FOR DRILL$ AND THE LIKE.

Specification of Letters Patent.

Patented May 13, 1919.

Application filed January 18, 1911. Serial No. 603,218.

To all whom it may concern:

Be it known that I, FRANK H. Minis, a citizen of the United States, residing in the city of Camden, State of New Jersey, have invented certain new and useful Improvements in Power-Transmitting Mechanism for Drills and the like, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention has for its object the pro vision of an organized power-transmitting mechanism which is direct-acting, compact, and of great power, operated by a motor, and comprising as its characteristic features a duplex worm-gear of novel construction, actuated by a pair of rotatable shafts arranged in parallelism, the worm-wheel element of the Worm-gear comprising means to directly transmit the power of the gear to a rotatable element, such as a gear wheel, a spindle or a drill. In the accompanying drawings described in the following specification, I have shown and described it as applied to and forming part of a portable power drill, for which purpose it has marked and special utility; and for that purpose I prefer to use as the motor element, a reciproeating engine, adapted to be operated by compressed air or other fluid pressure, and

comprising a new mechanical movement patented to me by Letters Patent No. 893,258 dated July 14:, 1908, adapted to directly convert reciprocatory into rotary motion, with reversing devices therefor. I

It will be observed from the drawings and description that applied to such a use, in the manner and by the means shown, the concrete result is a portable drill having as its actuating elements a series of associated power mechanisms operating in unison and supplementing and balancing one another in the application and increase of power; that it embodies all the propellingnlechanism within itself, with valve-mechanism ,in-

stantly controlling its operation, and is equipped with reversing mechanism readily adaptlng it to ta ping as Well as drilling without change 0 parts, and is so compact in the disposition of its elements that it may be used for corner drilling Where room is limited and where most pneumatic drills cannot be applied; the casing being of a size and form to operatively inclose the marine nism and no more, and moreover providing a perpetual lubricating chamber for the contained propelling mechanism and gearing, thus preventing overheating from the excessive friction created by the rapid action of the parts; the casing being made sufficiently tight that oil or the usual lubricant can be scaled up therein during operation; all the chambers containing any moving parts, forward of the cylinders and their valve mechanism, being constantly immersed in oil.

In the accompanying drawings illustrating my invention as applied to a power drill, Figure 1 is a plan view of the device in its containing and operating casing, and Fig. 2 aside elevation thereof. Fig. 3 is a like plan view as Fig. 1 but with the cover of the ,main casing as also the cover of the rear and valve-casing, removed; and Fig. 4. a central longitudinal section thereof, on the line AA of Fig. 3, including the casingcovers shown in Fig. 2.

Fig. 5 is a section on line B-B of Fig.

Fig. 6 is a section on line CC of Fig.

Fig. 7 is a section on line DD of Fig. looking rearward.

Fig. 8 is a section on line E-E of Fig. looking rearward.

Fig. 9 is a section on line F-F of Fig. 4, looking rearward.

Fig. 10 is a section on line GG of Fig. 4, looking in same direction. Fig. His 2. section on line HI-I of Fig. 4, looking in same direction.

Fig.12 is a rear end elevation of the connecting spindle-driving gearing, and

Fig. 13 is a plan view thereof partly in section.

Fig. 14 is a section, looking upward, taken online JJ of Fig. 4. I

Fig. 15 is a plan view of the reversing mechanism, and

Fig. 16, is a side elevation thereof. H Referring now to said drawings 1 and 2 indicate the connected parts of a suitable casing, of a shape adapted tocompactly contain the drill actuating mechanism and connecting gearing, and 3 and l indicate the removable covers thereon; the i'casing a Whole being ofsuch shape and character as to be readil held and manipulated by the operator. cans to detachably hold the eover and easing together, such indicated at 5 may be suitably employed. The for- Ward part 1 "of the casing is suitably shaped to contain the connected gearing hereinafter described, between the shafts of the duplex motor and the cog-gear which directly drives the tool-holding spindle; while the rear portion of the casing 1 isadapted to contain the motor cylinders, and the supplemental casing '2 to contain the valvemechanism. These several features, in the preferred form and character of the casing, are sufficiently, indeed clearly, indicated in Figs. 1 and 2 of the drawings,

If now we refer to Fig. 3 which is a plan view of the casing and its contents, with the cover removed, and to Fig. 4, on the same sheet, which is a central longitudinal section thereof, the relative arrangement of the elements will be apparent; the rear portion 2 of the casing containing a pair of cylinders 6 and 6 (see Figs. 5 and 6) in horizontal parallelism, and centrally over and between them the valve mechanism and its adjunc-- tive parts indicated generally at 7 in these Figs. 3 and 4..

The rear casing 2 is preferably made de-' tachable from the forward easing 1, and connected thereto by a pair of coinclding flanges 8 bolted together. The rear casing 2 may inclose or may constitute in itself the pair of cylinders 6, 6, see Fig. 6; and between the flanges 8, 8, is operatively supported a removable plate 12 operating as a cylinder head for both cylinders. The rear portion of the casing 2 is provided with a bored projection 8 which is the means for supplying compressed air orothermotive fluid to the cylinders. The bore of'thisprojeetion 8 leads to an aperture 9, which communicates wlth apertures 10, governed by a rotary valve 11, and leading to the cylinders. These'apertures are formed in the base of a valve-chest 13, and another aperture 14 in the forward end thereof also leads to the opposite ends of the cylinders. Resting in said valve chest is operatively supported the rotary valve 11,

which is-hollow andprovided with ports 15 at its opposite ends on opposite sides of its periphery. The exhaust is provided for by cut-away portions 15, see Fig. 4. The action of the valve, in its various positions, is shown in Figs. 9, 10 and 11. Rotary motion is imparted to the-valve 11, which carries spindle 16, the latter entering a reversing sleeve 17, carrying a-grooved collar 1'8. The sleeve 17 v has a backward and forward slidingyaswell as a rotary motion, at oneend'on the spindle 1'6, and at the other end on a. valve rod wayoperatethe rotary valve toapproprion the rear end on one of the shafts 35 (see Fig. 8) which is actuated by one of the spirally-grooved heads 28 hereinafter referred to. The reversing mechanism, which directly acts on the rotary valve 11, is shown in detached sections Figs. 15 and 16, wherein it will be seen that a pin 24: on the end of a rod 25 plays in the groove 18 of the sliding collar; while the other end is operatively connected to an actuating lever with handle 26 extending through the cover of the casing.

The pair of cylinders 6, 6, contain each a piston 27, each of which imparts a backward and forward reciprocating motion to a connected piston rod 28. These piston. rods are flat and setedgewise and pass through elongated openings in the cylinder head, and thence between a pair of adjustable rolls 25), 29, (see Fig. 7) which latter are acted on by a vertically-slidingtapered wedge 30 raised or lowered by a locking nut 31. This construction operates as a guide for thepiston rods, preventing all tendency to rotary or vibratory movement, and takes the place of the usual cross-head in a reci 'aroeating engine. A further bearing plate 37 rests upon the cylindrical ends of the heads to pre vent any rear end vibratory movement of the heads.

In order to prevent leakage of the elongated apertures in the cylinder head 12 where the piston rods pass through, I recess the inner face of the head around the apertures, apply a packing 32 in said recess, and hold the packing in place by a thin sheet spring metal plate 33, such as thin steel or spring brass; with the result that on the outward movement of the piston the air-pressure will be against this spring plate, while on the inward movement the spring holds the packing in operative position.

Each of the pair of spiral grooved heads 23 is constructed and actuates substantially as shown in my prior U. S. Patent 893,258 dated July 1-1, 1908. Sufiicient therefore to say that the rotary movement, as therein described, is imparted thereto by the actuating pin on the head of the flat reciprocating piston rod. One head 28 is always a quarter revolution in advance of the other. The outer end of the hollow head 23 has secured fixedly to it, a shaft 36 which therefore has like rotary movement.

The shaft'36 is supported in a pair of divided bearings 53 (see Fig. and 54- see Figs. 5 and 6) and between them a divided box 55 and 55. The upper half of divided bearing 53is supplied with a boss 56 (see Fig. 6) operating as a bearing for shaft of gear 21.

Fixedly mounted within the casing 1 is a center of the body portion 38,

median line through each of the threads brachet-bearing 57, with a curved face for shaft 36, and a removable half top 57 similarly curved. The fixed portion 57 of this bracket hearing has a rearwardly-extending portion 58 (see Fig 1) which serves as a bearing for end of valve rod 20.

That portion of shaft 36 rearward of the gears 21 and 22 is threaded as at 60 (Fig. 5) for the purpose of holding in place the spirallygrooved heads 23 and particularly taking up the end thrust, and a collar '61 see Fig. 8) on said threaded portion of shaft 60 fixes the parts in any positionof adjustment as to wear or longitudinal thrust, and a nut 62 holds the collar.

()n theextreme end of each of the shafts 36, is an integrally-constructed worm screw, best shown at 38 and 38 respectively, in Fig-L13.

31s the pair of shafts 36 rotate toward each other, as shown in the drawings, these screws 38 and 38 also so rotate with re? spect to each other. The body portion 38 of these screws is taperedfrom its baseoutward; the annular periphery of the tapered body is concaved; and the face of the concavity is provided with a spiral thread 39 of progressively varying diameter orwidth in its series of convolutions. The convolu tions of the spiral thread 39 being on the face of a concaved tapered periphery, necessarily are not in parallel straight planes, and the median line through each of the threads in the series would therefore have a different angle, relatively to each other, and to a straight line drawn through the longitudinal and yet the would pass throughtheaxial center 40 of the connecting gear 41. The worm screws 38 and 38 are alike in all respects, and capable of rotating the worm wheel 11 and tool wheel is afiat annular ring, asindicated in Figs. 12 and 13, formed on and preferably integral with the upper end of the 1 tool holder; and it is provided with a concave periphery the face of which has teeth 13 which are preferably thicker in the center than at their ends, as indicated in Fig. 12,

for the purpose of causing them to accord with the direction of and mesh fully with the thread 39 on the concaved tapered periphery of the worm screws 38 and 38 The result of this construction, of each of said elements, is to provide a short worn'r screw, with. the power of a long worm screw of usual construction, and capable of actuating the worm wheel in either direction.

The worm wheel 41 is mounted fast on and is preferably an integral part of a tool holder for detachably holding and actuating a drilling or tapping tool, and is so shown.

The tool-holder has a portion 45 of re1atively narrowed diameter, the base, of whichan Lip-movement to i may be briefly holder, in either direction. The worm 1 a rotary whereby the drilling is taperedoutwardly and downwardly, as

also the top edge of the worm gear 41, to receive 3/661168 of tapered anti-friction rolls a7. 1 1

The portion of said head below the wormgear 5L1, and indicated at 15 has a reduced screw fitted in a sleeve d6 the latter having a shoulder ifi to limit the up-moveznent of the feed-screw a9, while said sleeve 4C6 itself is limited in up-movement by contact with an annular stop 15" on the inner face of the bore of the bearing-guide head 4:8. The result is that on turning feed-screw t9, the sleeve 16 is not moved upward until the screw 4:9 is brought to a stop by shoulder 46, andthereafter sleeve 16 will be given withdraw it from hollow portion X of head 45, until likewise brought into contact with the aforesaid stop in the guiding head, and on downward movementby contact with base 50 of said head as. Said part 15 has a projecting and eXternally threaded portion t5, the latter to hold the removable tool-holder, the bore 51 therein being to allow ,removal of the tool without removing its holder. The tool and its holder are indicated at 52, in Fig. 6, in position. i i

The operation of the device as a whole. stated, as follows: Motive fluid being supplied to the cylinders,

through the rotary valve, the pistons re-- ciprocate in accordance with the setting of fore mentioned, are set on the quarter-turn, so that one is always a quarterrrevolution ahead ofthe other, and both impart a rotary motion to their shafts 36 which carry the gears 38 and 38 which in turn impart. motion to thetool-holding head through thegear 4C1 thereon. The actuating cylinder pistons and spirally-grooved heads may be reversed in motion a by means of the valve-reversing mechanism described, tool can be given a re verse rotary motion, a most important feature in using my device for tapping purposes.

While I have shown for the purpose of exemplifying one useful application of my novel power-transmitting mechanism, a novel engine element, its valves and connecting actuating and reversing devices, the separate containing casing for the complete power drill, and novel elements constituting the drill holder, I reserve these features for divisional patent applications, hence have not separately claimed the same herei Having thus described my invention, I

v impart its motion 7 tion,

"Copies of this patent may be obtained for claim as new and desire to secure by Letters Patent 1. Power transmitting mechanism comprising in combination, a support, a rotatab-ly driven shaft, a conical worm screw tapered from its base outward and fixedly mounted on the free end of said shaft, said worm having a longitudinally concaved periphery, the concave face of which is spirally threaded, the convolutions thereof being of relatively different angularity and also of progressively varying diameter, and a: peripherally concaved worm wheel the teeth of which are thicker in the center than at their ends, operatively meshing with said worm, and provided with means adapted to tea rotary machine element.

2. Power transmitting mechanism comprising in combination a support, a pair of shafts arranged in parallelism and adapted to be rotated continuously in either direca pair of oppositely disposed conical Worms fixedly mounted on the ends of said shafts,-said'worms having a tapered and lon- 'gitudinally concaved periphery with a spiral thread the convolutions whereof have a different angle relatively to each other, a Worm wheel operatively interposed between the said worms and provided with an elongated end adaptedto' impart its motion to a rotary machine element.

3. Power transmitting mechanism comprising in combination a support, a rotatably driven shaft, a conical worm fixedly mounted on the free end thereof, said worm having a longitudinally concaved tapered periphery which is spirally threaded, the

convolutions whereof have a different angle wormson the freeends of said shafts, the

peripheries of said worms being tapered from the base outward and longitudinally concaved and spirally threaded in such manner that the convolutions thereof have a different angle relatively to each other; a worm wheel operatively interposed between said worm screws, and provided with an elongated end adapted to directly impart its motion to a rotary machine element.

5. Power transmitting mechanism comprising in combination a support, a pair of parallel shafts adapted to be rotated in unison, in either direction, a pair of complemental conical worms on the free ends of said shafts, the peripheries of said Worms being tapered and concaved from the base outward and provided with a spiral thread the several convolutions of which are of progressively varying diameter, an interposed worm wheel having teeth longitudinally con caved, meshing with the thread of each of said worms, and ed to directly impart its motion to a rotary machine element.

6. Power transmitting mechanism comprising in combination a support, a pair of parallel shafts, adapted to be rotated continuously and in either direction, but in unison, means to reverse the direction of rotation of said shafts, a pair of complemental conical worms on the free ends of said shafts, the peripheries of said worms being tapered and concaved from the base outward and provided with a spiral thread the convolutions of which are of progressively varying diameters, an interposed worm wheel having teeth adapted to be operatively engaged by said worms, and provided with an elongated end adapted to impart its motion directly to a rotary machine element.

In testimony whereof, I have hereunto aflixed my signature this thirty-first day of December A. D. 1910.

FRANK H. MILLS.

Witnesses A. M. BIDDLE, R. A. DUNLAP.

five cents each, by addressing the Commissioner 0! Patents, Washington, D. 0."

provided with means adapt 

